The total amount of candy sold at cassandra's candy corner can be represented by the function c(x) = 4x3 + 16x2 + 60x + 648, where x represents the number of years since the store opened. The amount of types of candy can be modeled by the linear function t(x) = 2x + 12. Which expression represents the amount of candy sold each year per type at cassandra's candy corner?.
